A mobile phone conventionally transmits various types of information to a user by means of a display on a display or sound from a speaker. Such visual or acoustic information transmission may be undesirable.
For example, if one receives e-mail during a meeting, he/she would hesitate to stare at the display in order to check information on the e-mail during the meeting. Of course, information on the e-mail cannot be transmitted to a user by sound during the meeting.